Salivary Electrolytes in Infants Receiving Digoxin

Abstract

Recent adult studies have suggested an increase in salivary K+ and Ca++ in patients receiving digitalis. In order to investigate this phenomenon in the pediatric patient, whole saliva electrolytes were studied in 32 hospitalized infants (mean age 10 weeks); 17 receiving digoxin (aean digoxin level 2.Ing/ml) and 15 controls. Simultaneous serum electrolytes were also measured. Mean salivary K+ was significantly increased, 25,4±3.7mEq/l in the digitalised infants when compared to controls, 21.6±3mEq/l (p < 01). Mean salivary Ca++ was also elevated in the infants receiving digoxin, 4.3±2.8mEq/l versus controls 3.0±.96mEq/l (p < .05). The K+ x Ca++ product was 111.4±84.0 in infants receiving digoxin and 65.3±27.1 for controls (p < .025). Salivary Na+ was not different in the two groups. Serum K+ was elevated in the group receiving digoxin 5.1±.69 as compared to controls 4.6±.68 (p < .05) but serum Ca++ and Na+ concentration were similar. The mean salivary electrolyte concentrations in control infants and those receiving digoxin were comparable to levels reported for adults. The Increase in K+ concentration in saliva of infants receiving digoxin with no change in salivary Na+ lends support to the hypothesis that the increase in K+ in saliva is due to K+ loss from cells or elevated plasma K+ rather than inhibition of Na+/K+ exchange.